In recent years, advances in miniaturization have generated a great variety of personal electronic devices. Indeed, many people have come to depend on cellular telephones, electronic address books, personal digital assistants (PDA's) and pagers for their day to day professional lives. Likewise, consumer electronics such as personal stereos and hand-held video games are common recreational devices.
A feature common to all these personal electronic is the need for some type of energy storage to supply power. Particularly with high drain devices such as cellular telephones, it is often necessary to carry multiple batteries and perhaps a charging station for even relatively short trips. The user must constantly track the remaining battery capacity for each device to ensure that the charge will hold for a desired length of time. Alternatively, the user must carry spare batteries. Since each electronic device typically has its own requirements and form factors, the user might be forced to carry several different spare batteries to power the various devices. It is also quite desirable to provide these personal electronic devices with rechargeable batteries, both for their relative economy and to minimize environmental impact. However, such recharging systems are rarely compatible. One device's charger often will not recharge another's battery, nor will that battery be usable with a different device.
Accordingly, there has been a need for a system to integrate the power supplies of multiple personal electronic devices. There has also been a need for a universal rechargeable battery which can be used to power a variety of devices. This invention satisfies these and other needs.